In recent years, there is a demand that computer devices such as a personal computer and a game machine have a variety of designs and, accordingly, it is supposed that information disk apparatuses mounted on these computer devices are installed in various directions.
It is known that the information disk apparatus is required to detect an installing direction thereof and change various kinds of control parameters according to the installing direction, thereby to perform high-speed recording/reproduction, enhance the accuracy of the recording/reproduction, increase a speed for seeking a target information track or the like.
Accordingly, there is generally adopted a method of preparing firmware in which an optimum control parameter is previously set for each installing direction, or a method of setting information according to the installing direction through an external jumper setting, switching means or the like, to set an optimum parameter.
Further, according to a method as described in Japanese Published Patent Application No. Hei.10-255287, an object lens, a pickup device which supports the object lens so that it is movable at least in the tracking direction, a pickup carrier member for carrying the pickup device, a tracking control circuit for driving the object lens in the direction perpendicular to tracks, a traverse control circuit for driving the pickup carrier member in the direction perpendicular to the tracks, a position detector for detecting the initial posture of the object lens with respect to the pickup, and a compensation circuit which supplies a compensation signal according to the output from the position detector to the tracking control circuit and the traverse control circuit are included, whereby tracking control and traverse control can be performed in an optimum state at all times, independently of an installed state of a device.
Further, there a method is also known in which a sensor means that detects the direction in which a disk drive is set is provided in a device, thereby to detect the direction in which the device is installed.
However, in the method of preparing firmware in which an optimum control parameter is previously set for each installing direction, and the method of setting an installing direction through the external jumper setting, switching means or the like, a user is required to change the setting of the installing direction every time the user changes the direction in which a computer device is installed. Accordingly, when an erroneous setting is performed, the information disk apparatus fails to achieve its original performance.
Also, in the method disclosed in the Japanese Published Patent Application No. Hei.10-255287, since a positional relationship between the object lens and the pickup is detected, an error is easily generated due to variations in traverse loads, and in a device having a mechanism with the object lens whose weight is significantly reduced, an amount of displacement of the object lens, which is caused by gravity, is small and, thus, an accurate installing direction is not always detected. Moreover, in the method employing an installing direction detection means, the sensor means increases the cost of the device and a space needed for installing the sensor means in the device becomes a problem.
The present invention is made to solve the above-described conventional problems and has for its object to provide an information disk apparatus and an information disk apparatus installing direction detection method, which enable accurate detection of the installing direction at all times without employing a sensor means and with no increase in the costs.